1. Field of the Invention
The present invention relates to a photomultiplier tube, more particularly to a large-size photomultiplier tube that multiplies electrons incident on an electron multiplier section by laminated multi-stage dynodes.
2. Related Background Art
Conventionally, a photomultiplier tube of this kind which is described in Japanese Patent Application Laid Open No. 59-151741 has been known. This photomultiplier tube comprises a photoelectric surface formed on one end of a cylindrical blind vacuum container, an electron multiplier section that has a plurality of laminated dynodes, which multiplies the incident photoelectrons, an anode (positive electrode) of a net shape that collects the electrons multiplied by the electron multiplier section as an output signal, and a final-stage dynode (reversal dynode) of flat plate shape. Consequently, the photoelectrons emitted from the photoelectric surface are multiplied at the electron multiplier section, and are reflected at the final-stage dynode. Thereafter, the photoelectrons are collected as an output signal at the anode.